The present invention relates to connection handling in communications networks and finds particular application in handling incorrect destination codes, such as misdialled telecommunications numbers.
A result of de-regulation of the telecommunications industry is that many network providers and regulatory bodies have altered the dialling code regimes of their networks to increase capacity and allow for increases in traffic volumes.
These changes in dialling code regimes have been accompanied by increases in the level of misdialled calls. In particular, the level of misdialled facsimile calls has tended to increase disproportionately compared to the level of misdialled voice calls.
This is because the error messages transmitted to fax terminals are usually the same audible error messages that are transmitted to voice terminals. For several reasons, these audible error messages are much less effective, in practice, when transmitted to facsimile terminals than when transmitted to voice terminals. For instance, the user of a facsimile terminal often has the speaker volume turned right down or will have moved away from the terminal.
When changes to dialling code regimes have been complex, it has been known to manually transmit fax messages from international exchanges to customers making misdialled fax calls. However, this manual system is resource intensive and accordingly does not provide an effective long-term solution.
It is also known to locate a fax based responder at local exchanges to advise users of the network that the fax terminal they are attempting to reach has changed numbers.
These responders are triggered by incoming calls and, in accordance with the protocol for fax transmission, the responder must establish a new connection with the terminal that made the dialling error before it can transmit its fax based error message.
This means that the cycle for disposing of misdialled fax calls by these devices is much longer than the cycle for disposing of misdialled voice calls. This is because a voice-based responder can rely on the duplex capability of standard voice circuits.
A key characteristic of these simple fax messaging devices is that they are associated with a single exchange line, which was previously used for a fax machine. They can only send a fax in response to a caller attempting to send fax to that particular exchange line number.
Accordingly such simple devices would not be able to respond to widespread misdialling as a result of changed network dialling code regimes.
A fax based responder of the above mentioned type is disclosed in Dutch patent application No. 9400275. In this disclosure an automatic fax answering machine is installed in a telephone exchange for a respective tax subscriber line. The fax answering machine is connected to the old subscriber number and is set up to automatically send an appropriate fax message to a calling subscriber. A failed communications attempt to the old number is dealt with immediately by the answering machine in one of two ways. In one way, the answering machine interrupts the fax connection protocol before the fax is sent and converts the incoming call into a call from the exchange to the calling subscriber number and sends the fax message immediately. In another way the answering machine dis connects the incoming fax call and sets up a new call from the exchange to the calling subscriber number.
According to a first aspect of the present invention there is provided apparatus for transmitting information, by means of a communication network, to any one of a plurality of communications terminals connected to said network, which said transmission is in response to a failed communications attempt by any one of said terminals, which apparatus comprises:
i) identification means for identifying a network address of a terminal making a failed communications attempt;
ii) at least one storage means configured to store a plurality of network addresses so identified; and
iii) information transmission means for transmitting information to a terminal making a failed communications attempt;
wherein said information transmission means is adapted to access said storage means, to locate a network address stored therein and to transmit said information to a network address so located.
According to a second aspect of the present invention there is provided a method of operating a communications network interconnecting a plurality of communications terminals, said method comprising the steps of:
1) detecting a failed communication attempt by a communications terminal;
2) identifying said communication terminal""s network address;
3) storing information in a data store configured to store a plurality of network addresses, which information is at least in part dependent on the network address of said communications terminal;
4) retrieving said information from said data store; and
5) using at least part of the information so retrieved to transmit a communications signal to said terminal.
xe2x80x9cFailed communications attemptxe2x80x9d means in this context a communications attempt which has not succeeded in being connected, at least at first instance. For instance, a misdialled telephone or facsimile number will become a failed communications attempt if the number does not actually represent a network address, for instance because of a code change. (Some misdialled numbers will of course make a connection if the number is still a viable network address, for instance when a user simply uses the wrong number.)
The identification means may identify a network address of a terminal making a failed communications attempt, for instance by selecting a field in incoming data concerning the failed communications attempt, which field contains said network address.
Embodiments of the present invention effectively decouple the process of detecting a misdial from the process of transmitting an error message to the terminal making the misdial. In this way, it becomes possible, for instance, for detection of dialling errors and the provision of a response to happen at substantially the same rates, even when the transmission technology concerned is unidirectional, such as fax terminals, and the transmission of error messages therefore takes considerably longer than identifying the network address of a terminal making a failed communications attempt. This is the case as long as the apparatus is provided with a capacity for sending a greater number of error messages at any one time than the number of network addresses it is identifying at any one time. The apparatus can then read out several network addresses from the storage means and start transmitting error messages to them concurrently, rather than having to deal with each failed communications attempt immediately after receipt.
Transmitting information concurrently with identifying dialling errors enables the apparatus to cycle through calls from terminals using uni-directional protocols, such as the fax protocol, at a similar rate to the rate at which it cycles through misdialled voice calls which use a duplex protocol.
An unexpected and powerful advantage of storing the network addresses arises in that the data inherent therein can be analysed and used in embodiments of the invention for instance to select messages to be sent to future misdialling users.
Advantageously, embodiments of the present invention may further comprise means for identifying communications protocols used by said terminals when making said failed connection attempts. For instance, said apparatus may be adapted to store identified network addresses in the data store in response to identifying a uni-directional protocol.
In particular, the network addresses may be stored in response to the apparatus identifying a fax protocol. Such a network address may be identified by Calling Line Identification (CLI) information provided by many network providers.
Preferably said apparatus is further adapted such that in use transmission of information by said transmission means in response to a failed communications attempt by a first terminal may be performed concurrently with identifying the network address of a second terminal making a failed communications attempt.
The parallel operation of identifying a failed communications attempt concurrently with transmitting information to a different terminal that has previously made a failed communications attempt provides allows a number of misdialled calls to be handled simultaneously.
Preferably the information transmission means is adapted to transmit concurrently information to each of a plurality of network addresses.